Combination stamp, crushing, and grinding mill.



A. F. LEVITT. COMBINATION STAMP, CR USHING, AND GRINDING MILL.APPLICATION FILED MAR, 8,19I7- r 1,247,293, I v Patented N0v.20,1917.

amass F; IiEviT T, satin? assassins, unsanitar oo'iviiiiva'rioivsTAivrr,came as, are: GItiItDING? anti tenses.

Patented Nov: so, 191W.

Application filedllfarh 8; 1917; Serial No. 153323;

To all whom it may' 00mm.-

Be it known thatI, ARTHUR F. Lnvrrr a citizen of the United States,residing at South Pasadena, in the county of LosAnge les and State ofCaliforniayhave invented new and useful Improvements in CombinationStamp, Crushing, and Grinding Mills, of which the following is aspecification;

This invention relates to an oremill and particularly pertains to acombined crushing' and grinding mill for use in the'amalgamation processof ore recovery. 1

It is an object of this invention'to provide a mill for thetreatmentofores and the re covery of precious metals "which ha's'a combinedactionto stamp or crush the ore and' to thereafter grind it by acontinuous operation anduseof'one set of operating elements.

Another object ofthis inventionis to provide a mill for the treatment ofores and the recovery of precious metals therefrom which will subjectthe ore to a simultaneous crushing and grinding blow, thereby causingthe ore to be forcefullystruck and ground during a single movement thusinsuring that the ore will be quickly separated from the metal withoutbecoming lost and without the amalgam'being floured, as is common instamp mills and the like, where the ore is given a direct and powerfulstamping stroke.

-Another object of this invention is to pro vide an. ore treatingmachine which will cause the ore to continuously move over the grindingfloor and-will permit itito fall at a certain intervals in a manner todisintegrate it and permit it to come in contact with the amalgamwithout being struck by the grinde ing element. V y t 3 Another objectof this invention is 'to pro" vide an ore mill whichwill positively andautomatically clearitself of the tailings and insure that the screensthrough which; the tailingsfiow willbe maintained in a desirable andcleaned condition.

Another objectof this invention is to pr'ovide a grinding mill designedalong; the lines off'an arrastrewhich isfitted with a floor of peculiarconstruction so that pockets of amalgam may .be distributed over itsgrinding-surface in a mann'erto entrapthe metals freed from the ore andcause them to be recovered withoutidifficulty.

Another object of this invention is to pro-' vide means for retainingthe large; particles of ore within the milluntilfthey have beenthoroughly pulverized and at the same time permitting the tailings tobedrawn from the mill in a continuous manner without carrying away theal'nalgam'.

Another ob'ect ofthisinVentiori is to pro vide grinding andcrushingelements which may be easily replaced'andwhi'ch are drawn by a mechanismof simpleconstruction.

Another object is to provide feed means forthe mill which willpermit-raw material to be continuo'uslyfedto thegrin'ding floor withoutinterruption of the-operation of the driving mechanism.

Another object of this invention is to provide means whereby'thegrinding floor may be easllyj uncovered and the amalgam' cleanedtherefrom.

It is a further object to provide a mill of the above class which may beconstructed of stone,"metal, or other materials and which will operateequally well regardlessof the material from whichit isconstructed,*thereby providinga mill which may be easily set up inremote localities and inexpensively operated;

Other objects will appear hereinafter.

The invention is illustrated, byway ofexample; in the accompanyingdrawings in which: V

Figure 1 is a view in side-elevation illustratingthe' mill as assembledfor operation and with parts broken away to disclose the detailformation of the grinding floor.

Fig. 2 is a view in plan elevation'and sec tionas seen taken on a linedirectly below thedriving head and as disclosing the dis tribution ofgrinding members around the floor and the manner in which waterissupplied to said floor. 1

Fig. 3 is an enlarged fragmentary detail elevation showing how a grinderjumps an amalgamating pocket.

Referring morejparticularly to the drawings, 10 indicates a base, whichis here shown as circular in formation and supported upon supportingposts 11. This base may be formed of any desired material butispreferablyformed of concrete and is adapted to' provide a support fora grindingfloor 12;

rati'on is disposed at substantially twenty/5 two and one-half degreesto the vertical, and thewall 16 is preferably formed at right angles tothis face.v Various materials treated andthe speed ofoperation willdetermine this angle, however. be seen that a V-shaped pocket 14 isformed for the reception of amalgam to be utilized in the recovery ofthe ore. Surrounding the,

grinding floor is a wire inolosure 17 which prevents large pieces of orefrom pass ng out with the tailings into a sluice-way 18. The inclosureis bounded along its lower edge by a continuous baflle strip 19 whichpartially closes the outer ends of the serrations and-forms a trap for.the amalgam and fine stuffsettling therein.

A center-shaft 20 extends vertically through the base and provides amounting for a drivin'g'head 21. This head is disposed in ajhorizontalplane and is fitted with a series of drag chains 22 which depend fromits under face and are connected to grinding members '23. These members,as particularly shown in Fig. 1 of the drawings, have a fiat faceadapted to bear upon the inclined face 15 of eachserration as thedriving head rotates in the direction of the I arrow -1a--. The'rearface of the grinding members is here shown as disposed at an angle ofless thanninety degrees to the grinding face, although this angle may bevaried and thereby will provide clearance "16 between it and thevertically inclined face 16 of the serrations. This allows the grindingelements, which are of considerable weight, to fall'from the apex of thetooth to the gullet with considerable force.

This will crush the ore and as the grinding elementis dragged 'alongtheface 1 5 'of'the serration. the ore thus crushed will be ground. Thedriving head'may be rotated by any desired source of power and is hereshown as formed with a rim gear 24 in and is formed with a downwardlyturned elbow 30; An inturned trough 31 is secured at the bottom ofthechute and acts to direct the ore from the hopper in between the drivinghead and the grinding floor. It will be noted that due to the manner inwhich the grinding elements are connected to the head, the ore will fallaround and over these elements and will finally settle within thepockets of the'grinding floor as the operation ofthe machine continuesand thereby insure that the reduced ore will be thoroughly subjected tothe action ofan amalga- It will thus tion of the arrowaandthe drivingele mating agent. The drivingstructiire is reinforced by means of sideposts 32 and 33 which extend vertically at-opposite sides of the milland provide support for stay rods Qfl and 35 connecting with'a' collar36 This collar is positioned around the upper end of the center shaft 20and actsto 'giveit stability. p I p In operation, ore or other materialto be treated is plaoed withinjthe.hopper 28 and fed "down'throu'gh thechute 29 to the grinding floor; Simultaneouswith which action. the;driving head 21is rotated. in the direcments 28 and thus drawn overthegrinding s0 floor. A'sthese elements move alongtheir course oftravelthey will successivelyride up along the inclined faces 15 of theserrations and thereafter will fall with consider-' able force upontheface of the succeeding serration. The 'angle of theface 1G and thespeedat which the grinding elements move will determine the approximatepoint at which theelement will strike the face;of each ser-rat-ion afterhaving fallen from the crestof t'lie'preceding one. In any case, the

operation ofthe machine is such as to insure that the grinding elementwill not fall d-iv rectly into the gullet of. theserration, as thislowermost crevice is reserved as apocket' for theramalgam and'pulp whichis drawn over thecrest of the serration and permitted to amalgama'tetherein. Due'tothe fact that the grinding element willnot strike thisbody of pulp, the amalgam will be prevented from flouring and the pulpin combination therewith will be agitatedto be thoroughly subjectedtothe amalgamatingetfect of the agent. lAs the grinding element'strikesthe inclined face 'of' each serrati'on it will deliver ablow- 'at anincline to "the face and thereby produce a combined-crushing andgrinding action. The force ofthis obliquely delivered blow will causethepulp andfine. stuff to "splash outwardly through the screen 19 and intothe sluice-way '18 thus automaticallyclearing the grinding floor'ofuse-i less material. As the elements rideup over the inclined faces theywill continue to grind the pulp and 'reduce it; I This material will beraked over the crest of the serrations and permitted to" fall free intothe amalgam pockets. At the same time, water isgbeing delivered from thesprinkler pipe 37 and will'permit desirable results to be moreefliciently obtained. Whenthe mill has been operated asu-ificientperiod'of time,'the driving head 21 may berais'ed upon theshaft 20 and the 'grinding elements removed fromthe floor; The amalgammay then be drawn off f'romth'e grinding floor and the recovery of themetals completed; Especial attention is called to the V-shapedamalgamating pockets 14 produced by the angular ar rangement of thefroiit' moderately, inclined faces 15 of the serrations 14, and thenearly vertical rear face 16, together with the inclined rear faces ofthe grinding members 23, which produces the clearance 16 between agrinding memberand a serration as the grinding member passes from oneserration to the next, thereby causing the grinding member to jump theamalgam in the pocket 14.

It Will thus be seen that the mill here disclosed is simple in itsconstruction and at the same time produces a combined crushing andgrinding action by the continuous operation of its grinding members.

while I have shown the preferred construction of my ore mill as nowknown to me, it will be understood that various changes in thecombination construction, and arrangement of parts may be made by thoseskilled in the art without departing from the spirit of my invention.

1 claim:

1. In an ore mill, a circular grinding floor having radial serrationsextending upwardly, the front side of each serration being at a moderateincline and the rear side of each serration being substantially at rightangles to the front side, thereby forming V-shaped amalgamating pockets,amalgam in theamalgamating pockets, a grinding member having a flatlower face adapted to bear upon the front inclined faces of theserrations, said member having a rounded corner formed by its lower andrear faces to prevent the grinding member from seating Within theamalgainating pockets formed by the meeting of the adjacent serrations,a. rotating member above the grinding floor, and a connection betweenthe grinding member and the rotating member; so that the grinding memberis dragged from serration to serration; the angles, arrangement, andspeed being such that the grinding member will jump the pocket ofamalgam as it passes from one serration to the next.

2. In an ore mill, a circular grinding floor having radial serrationsextending upwardly; the front face of each serration being disposed at amoderate incline to the horizontal and the rear face of each serrationbeing substantially at right angles to the front face, thereby formingV-shaped amalgam pockets; the faces of which are exposed at angles tothe vertical and horizontal; amalgam in said pockets, a freely movinggrinding member having a flat lower face adapted to bear upon the frontinclined face of the serrations and a flat rear face disposedsubstantially at right angles to the lower face and formed with a curvedlower edge to prevent the grinding member from seating within the gulletof the amalgam pocket, a rotating member above the grinding floor, and aflexible connection between the grinding member and the rotating memberwhereby the grinding member may be dragged over the grinding floor andfrom serration to serration; the angles of the serrations and therounded rear corner of the grinding member serving to cause the grindingmember to jump from the front face of one ser'ation to the front face ofthe other without seating within the gullets of the serrations.

In testimony whereof I have signed my name to this specification.

ARTHUR F. LEVITT.

Gopies of this patent may be obtained for five cents each, by addressingthe Commissioner of Eatcntt, Washington, I). G.

